A refractory material made from secondary aluminum ash and its preparation method

Abstract

A refractory material using secondary alumina ash as raw material and its preparation method are disclosed. The preparation method of the refractory material using secondary alumina ash as raw material includes a mixture and water. The raw materials of the mixture include treated secondary alumina ash, attapulgite clay, limestone, modified mullite fiber, binder, and muscovite. The modified mullite fiber is prepared by impregnating mullite fiber in a mixture of liquid phenolic resin, silica powder, and isopropanol. After impregnation, the fiber is dried and heat-treated sequentially to obtain modified mullite fiber. The treated secondary alumina ash is processed by crushing the secondary alumina ash, followed by acid leaching and water washing, and finally drying to obtain treated secondary alumina ash. This invention enables the resource utilization of industrial solid waste and reduces the production cost of refractory materials. Furthermore, this refractory material exhibits excellent refractoriness, softening temperature, room temperature compressive strength, reheat linear change, and thermal shock resistance, making it suitable for high-temperature industrial kilns.

Description

Technical Field

[0001] This invention relates to the field of solid waste resource utilization technology in the aluminum industry, and in particular to a refractory material made from secondary aluminum ash and its preparation method. Background Technology

[0002] Aluminum is a crucial component in common refractory materials, with a high aluminum content, leading to substantial aluminum consumption during their production. The resulting secondary aluminum ash, if not properly disposed of, will not only occupy valuable land resources but also cause serious pollution to the atmosphere, soil, and water bodies due to its toxic components such as nitrides, fluorides, and chlorides, harming the ecological environment and human health. Furthermore, the idle storage of large quantities of secondary aluminum ash represents a significant waste of resources, as it typically contains over 60% alumina and approximately 5%-10% magnesium oxide, possessing considerable potential for utilization.

[0003] To address the challenges of aluminum ash disposal and achieve resource recycling, numerous technologies for preparing refractory materials from aluminum ash have been developed. However, the presence of various impurities in secondary aluminum ash, such as Mg, Ca, F, Fe, Cu, Zn, and Si, severely deteriorates the performance of the final refractory materials. This results in suboptimal performance in key indicators like strength, refractoriness, and high-temperature crack resistance, making it difficult to meet the increasingly stringent requirements of modern high-temperature industries. For example, in some high-temperature kilns, insufficient refractory strength leads to frequent lining damage, necessitating frequent repairs and replacements, increasing production costs and reducing efficiency. Insufficient refractoriness limits the kiln's operating temperature, hindering the implementation of new processes. Poor high-temperature crack resistance causes cracks in the refractory material during drastic temperature changes, leading to high-temperature gas leakage within the furnace, posing safety hazards, and accelerating the deterioration of the refractory material.

[0004] Therefore, in view of the shortcomings of the existing technology, it is necessary to provide a method for preparing refractory materials using secondary aluminum ash as raw material and the preparation method thereof to solve the shortcomings of the existing technology. Summary of the Invention

[0005] The primary objective of this invention is to overcome the shortcomings of existing technologies by providing a method for preparing refractory materials using secondary alumina ash as a raw material. The refractory material obtained by this method, using secondary alumina ash as the main raw material, exhibits high refractoriness and does not crack under high-temperature conditions.

[0006] The above-mentioned objectives of the present invention are achieved through the following technical measures:

[0007] A method for preparing refractory materials using secondary aluminum ash as raw material is provided, comprising a mixture and water; the raw materials of the mixture include treated secondary aluminum ash, attapulgite, limestone, modified mullite fiber, binder and muscovite.

[0008] Preferably, the above-mentioned modified mullite fiber is prepared by impregnating the mullite fiber in a mixture of liquid phenolic resin, silica powder and isopropanol, and then drying and heat-treating it in sequence after impregnation to obtain the modified mullite fiber.

[0009] Preferably, the above-mentioned secondary aluminum ash treatment method is to crush the secondary aluminum ash, then perform acid leaching and water washing in sequence, and finally dry it to obtain the secondary aluminum ash after treatment; in the secondary aluminum ash, the weight percentage of alumina is 70wt% to 80wt%, the weight percentage of magnesium oxide is 5wt% to 7wt%, and the weight percentage of silicon dioxide is less than 8wt%.

[0010] This invention relates to a method for preparing refractory materials using secondary aluminum ash as raw material, wherein the mixture comprises, by weight percentage:

[0011] Secondary aluminum ash after treatment: 65wt%~70wt%;

[0012] Attapulgite: 5wt%~8wt%;

[0013] Limestone: 2wt%–5wt%;

[0014] Modified mullite fiber: 5wt%~10wt%;

[0015] Adhesive: 3wt%~5wt%;

[0016] Muscovite: Balance.

[0017] This invention relates to a method for preparing refractory materials using secondary aluminum ash as raw material, wherein the mixture comprises, by weight percentage:

[0018] Secondary aluminum ash after treatment: 68.5 wt%;

[0019] Attapulgite: 6.5 wt%;

[0020] Limestone: 3.8 wt%;

[0021] Modified mullite fiber: 7.6 wt%;

[0022] Adhesive: 4.2 wt%;

[0023] Muscovite: Balance.

[0024] In the mixture, the mass ratio of liquid phenolic resin, silica powder and isopropanol is (10-15):(3-8):(60-80), and the mass ratio of mullite fiber to the mixture is (3-5):(5-10).

[0025] In the mixture, the mass ratio of liquid phenolic resin, silica powder and isopropanol is 12:6.5:72, and the mass ratio of mullite fiber to the mixture is 4:9.

[0026] Preferably, the preparation method of the above-mentioned modified mullite fiber is carried out by the following steps:

[0027] A1. Immerse the mullite fiber in a mixture of liquid phenolic resin and silica powder for 1 to 3 hours, and then remove the immersed mullite fiber.

[0028] A2. The mullite fibers impregnated in A1 are dried at a temperature of 70℃~90℃ for 8h~12h to obtain dried mullite fibers.

[0029] A3. The dried mullite fibers from A2 are heat-treated at a temperature of 750℃~900℃ for 4h-8h to obtain modified mullite fibers.

[0030] Preferably, the treatment method for the secondary aluminum ash after the above treatment is as follows:

[0031] B1. Crush the secondary aluminum ash to a mesh size of 400 or finer to obtain crushed secondary aluminum ash;

[0032] B2. Mix hydrochloric acid with a weight ratio of 1:(0.8~1) and a concentration of 5.0wt% with the crushed secondary aluminum ash from B1, stir at room temperature for 4h~8h, and then filter to obtain acid-leached secondary aluminum ash.

[0033] B3. Wash the acid-leached secondary aluminum ash from B2 with pure water until the pH of the washing solution is 6.5-7.5, and finally dry the solid to obtain the treated secondary aluminum ash.

[0034] Preferably, the preparation method of the above-mentioned modified mullite fiber is carried out by the following steps:

[0035] A1. Immerse the mullite fiber in a mixture of liquid phenolic resin and silica powder for 1-3 hours, and then remove the immersed mullite fiber.

[0036] A2. The mullite fibers impregnated in A1 are dried at 82.5℃ for 10 hours to obtain dried mullite fibers.

[0037] A3. The dried mullite fiber from A2 was heat-treated at 856℃ for 6 hours to obtain modified mullite fiber.

[0038] Preferably, the treatment method for the secondary aluminum ash after the above treatment is as follows:

[0039] B1. Crush the secondary aluminum ash to a mesh size of 400 or finer;

[0040] B2. Mix hydrochloric acid with a weight ratio of 1:0.85 and a concentration of 5.0 wt% with the crushed secondary aluminum ash from B1, stir at room temperature for 6 hours, and then filter to obtain acid-leached secondary aluminum ash.

[0041] B3. Wash the acid-leached secondary aluminum ash from B2 with pure water until the pH of the washing solution is 6.5-7.5, and finally dry the solid to obtain the treated secondary aluminum ash.

[0042] The method for preparing refractory materials using secondary aluminum ash as raw material according to the present invention comprises the following steps:

[0043] S1. Mix the raw materials according to the proportions, let them stand, and obtain the mixture;

[0044] S2. The mixture obtained in S1 is mixed with water and pressed into shape under pressure of 60MPa to 65MPa and pressure holding time of 30s to 120s to obtain a green body. The mass ratio of the mixture to water is 1:0.5 to 0.8.

[0045] S3. The blank is subjected to high-temperature calcination at a heating rate of 5℃ / min to 10℃ / min, a temperature of 1250℃ to 1550℃, and a time of 60min to 240min to obtain the refractory material.

[0046] The second objective of this invention is to overcome the shortcomings of existing technologies and provide a refractory material using secondary aluminum ash as a raw material. This refractory material using secondary aluminum ash as a raw material has high refractoriness and does not crack under high-temperature conditions.

[0047] The above-mentioned objectives of the present invention are achieved through the following technical measures:

[0048] A refractory material using secondary aluminum ash as raw material is provided, which is prepared by the above-mentioned method for preparing refractory materials using secondary aluminum ash as raw material.

[0049] This invention discloses a refractory material using secondary alumina ash as raw material and its preparation method. The method for preparing the refractory material using secondary alumina ash as raw material includes a mixture and water. The mixture comprises treated secondary alumina ash, attapulgite clay, limestone, modified mullite fiber, a binder, and muscovite. The modified mullite fiber is prepared by impregnating it in a mixture of liquid phenolic resin, silica powder, and isopropanol, followed by drying and heat treatment to obtain the modified mullite fiber. The treated secondary alumina ash is processed by crushing it, followed by acid leaching and water washing, and finally drying to obtain the treated secondary alumina ash. This invention's refractory material uses secondary alumina ash as the main raw material, achieving resource utilization of industrial solid waste and reducing refractory material production costs. Furthermore, the refractory material obtained by this invention exhibits excellent refractoriness, softening temperature, room temperature compressive strength, reheat linear change, and thermal shock resistance, making it suitable for high-temperature industrial kilns. Detailed Implementation

[0050] The technical solution of the present invention will be further described with reference to the following embodiments. Unless otherwise specified, the raw materials used in the following embodiments are all commercially available products. Specifically, the adhesive of the present invention is sodium carboxymethyl cellulose (CMC), the liquid phenolic resin was purchased from Wuxi Mingyang Adhesive Materials Co., Ltd. and is model 2123, the silica powder was purchased from Anyang Zhongyu Jinming Silicon Industry Co., Ltd. and is model 5N silica powder, and the mullite fiber was purchased from Zibo Yubang Energy-Saving Materials Co., Ltd. and is model SS-PMF1700.

[0051] Example 1

[0052] A method for preparing refractory materials using secondary aluminum ash as raw material, comprising a mixture and water; the raw materials of the mixture include treated secondary aluminum ash, attapulgite clay, limestone, modified mullite fiber, binder and muscovite.

[0053] In the mixture, by weight percentage:

[0054] Secondary aluminum ash after treatment: 65wt%~70wt%;

[0055] Attapulgite: 5wt%~8wt%;

[0056] Limestone: 2wt%–5wt%;

[0057] Modified mullite fiber: 5wt%~10wt%;

[0058] Adhesive: 3wt%~5wt%;

[0059] Muscovite: Balance.

[0060] The modified mullite fiber is prepared by impregnating mullite fiber in a mixture of liquid phenolic resin, silica powder, and isopropanol. After impregnation, the fiber is dried and heat-treated sequentially to obtain the modified mullite fiber. The mass ratio of liquid phenolic resin, silica powder, and isopropanol in the mixture is (10-15):(3-8):(60-80), and the mass ratio of mullite fiber to the mixture is (3-5):(5-10).

[0061] The preparation method of modified mullite fiber consists of the following steps:

[0062] A1. Immerse the mullite fiber in a mixture of liquid phenolic resin and silica powder for 1 to 3 hours, and then remove the immersed mullite fiber.

[0063] A2. The mullite fibers impregnated in A1 are dried at a temperature of 70℃~90℃ for 8h~12h to obtain dried mullite fibers.

[0064] A3. The dried mullite fibers from A2 are heat-treated at a temperature of 750℃~900℃ for 4h-8h to obtain modified mullite fibers.

[0065] The treatment method for secondary aluminum ash is to crush the secondary aluminum ash, then sequentially acid-soak and water-wash it, and finally dry it to obtain the treated secondary aluminum ash.

[0066] The treatment method for secondary aluminum ash after processing is as follows:

[0067] B1. Crush the secondary aluminum ash to a mesh size of 400 or finer to obtain crushed secondary aluminum ash;

[0068] B2. Mix hydrochloric acid with a weight ratio of 1:(0.8~1) and a concentration of 5.0wt% with the crushed secondary aluminum ash from B1, stir at room temperature for 4h~8h, and then filter to obtain acid-leached secondary aluminum ash.

[0069] B3. Wash the acid-leached secondary aluminum ash from B2 with pure water until the pH of the washing solution is 6.5-7.5, and finally dry the solid to obtain the treated secondary aluminum ash.

[0070] In this invention, the secondary aluminum ash contains aluminum oxide at a weight ratio of 65wt% to 75wt%, magnesium oxide at a weight ratio of 5wt% to 7wt%, and silicon dioxide at a weight ratio of less than 8wt%.

[0071] It should be noted that, since secondary aluminum ash contains small amounts of elemental metals, alkaline earth metal oxides, non-metallic oxides, and some AlN, this invention removes low-melting-point, volatile, easily hydrated, and gas-generating components by acid leaching and water washing of the secondary aluminum ash. This reduces interference from impurity ions, improves sintering performance, enriches high-refractory phases, and eliminates structural hazards such as expansion, cracking, and porosity. Ultimately, this significantly improves the refractoriness, structural stability, and high-temperature strength of the refractory material, enabling it to meet the requirements of high-temperature industrial environments. The modified mullite fiber of this invention functions by adding carbon and silicon sources to form silicon carbide, thereby doping the mullite fiber with silicon carbide. This allows the refractory material to form a network skeleton with other materials. When the refractory material develops microcracks due to thermal stress, the modified mullite fiber can dissipate energy through bridging and pull-out effects, preventing crack propagation. Furthermore, the modified mullite fiber can improve the tensile strength and fracture toughness of the fiber itself, making it less prone to embrittlement at high temperatures and reducing the overall thermal expansion difference of the material, thus reducing structural damage caused by thermal shock.

[0072] The method for preparing refractory materials using secondary aluminum ash as raw material according to the present invention comprises the following steps:

[0073] S1. Mix the raw materials of the mixture according to the proportion, let it stand, and obtain the mixture.

[0074] S2. The mixture obtained in S1 is mixed with water and pressed into a blank under a pressure of 60MPa to 65MPa and a holding time of 30s to 120s. The mass ratio of the mixture to water is 1:0.5 to 0.8.

[0075] S3. The green body is subjected to high-temperature calcination. The heating rate of high-temperature calcination is 5℃ / min~10℃ / min, the temperature is 1250℃~1550℃, and the time is 60min~240min to obtain refractory material.

[0076] The refractory material of the present invention uses secondary alumina ash as the main raw material, which can realize the resource utilization of industrial solid waste and reduce the production cost of refractory materials. Moreover, the refractory material obtained by the present invention has excellent refractoriness, softening temperature, room temperature compressive strength, reheat linear change and thermal shock resistance. Therefore, the refractory material can be used in high-temperature industrial kilns.

[0077] Example 2

[0078] A method for preparing refractory materials using secondary aluminum ash as raw material, which is otherwise the same as in Example 1, except that:

[0079] In the mixture, by weight percentage:

[0080] Secondary aluminum ash after treatment: 65wt%;

[0081] Attapulgite: 8 wt%;

[0082] Limestone: 5 wt%;

[0083] Modified mullite fiber: 10 wt%;

[0084] Adhesive: 3wt%;

[0085] Muscovite: Balance.

[0086] The modified mullite fiber is prepared by impregnating mullite fiber in a mixture of liquid phenolic resin, silica powder, and isopropanol. After impregnation, the fiber is dried and heat-treated sequentially to obtain the modified mullite fiber. The mass ratio of liquid phenolic resin, silica powder, and isopropanol in the mixture is 15:3:80, and the mass ratio of mullite fiber to the mixture is 3:5.

[0087] The preparation method of modified mullite fiber consists of the following steps:

[0088] A1. Immerse the mullite fiber in a mixture of liquid phenolic resin and silica powder for 1 hour, and then remove the immersed mullite fiber.

[0089] A2. The mullite fibers impregnated in A1 are dried at 70°C for 8 hours to obtain dried mullite fibers.

[0090] A3. The dried mullite fiber from A2 was heat-treated at 750℃ for 8 hours to obtain modified mullite fiber.

[0091] The treatment method for secondary aluminum ash is to crush the secondary aluminum ash, then sequentially acid-soak and water-wash it, and finally dry it to obtain the treated secondary aluminum ash.

[0092] The treatment method for secondary aluminum ash after processing is as follows:

[0093] B1. Crush the secondary aluminum ash to a mesh size of 400 or finer to obtain crushed secondary aluminum ash;

[0094] B2. Mix hydrochloric acid with a weight ratio of 1:0.8 and a concentration of 5.0 wt% with the crushed secondary aluminum ash from B1, stir at room temperature for 4 hours, and then filter to obtain acid-leached secondary aluminum ash.

[0095] B3. Wash the acid-leached secondary aluminum ash from B2 with pure water until the pH of the washing solution is 6.5, and finally dry the solid to obtain the treated secondary aluminum ash.

[0096] The elemental composition of the secondary aluminum ash from a certain recycled aluminum plant used in this embodiment is shown in Table 1:

[0097] Table 1. Composition of secondary aluminum ash in this embodiment

[0098]

[0099] The method for preparing refractory materials using secondary aluminum ash as raw material according to the present invention comprises the following steps:

[0100] S1. Mix the raw materials of the mixture according to the proportion, let it stand, and obtain the mixture.

[0101] S2. The mixture obtained in S1 is mixed with water and pressed into a blank under a pressure of 60 MPa and a holding time of 120 s. The mass ratio of the mixture to water is 1:0.8.

[0102] S3. The green body is subjected to high-temperature calcination at a heating rate of 10℃ / min, a temperature of 1550℃, and a time of 240min to obtain refractory material.

[0103] Example 3

[0104] A method for preparing refractory materials using secondary aluminum ash as raw material, which is otherwise the same as in Example 1, except that:

[0105] In the mixture, by weight percentage:

[0106] Secondary aluminum ash after treatment: 70wt%;

[0107] Attapulgite: 5wt%;

[0108] Limestone: 2wt%;

[0109] Modified mullite fiber: 5 wt%;

[0110] Adhesive: 5 wt%;

[0111] Muscovite: Balance.

[0112] The modified mullite fiber is prepared by impregnating mullite fiber in a mixture of liquid phenolic resin, silica powder, and isopropanol. After impregnation, the fiber is dried and heat-treated sequentially to obtain the modified mullite fiber. The mass ratio of liquid phenolic resin, silica powder, and isopropanol in the mixture is 10:8:60, and the mass ratio of mullite fiber to the mixture is 5:10.

[0113] The preparation method of modified mullite fiber consists of the following steps:

[0114] A1. Immerse the mullite fiber in a mixture of liquid phenolic resin and silica powder for 1 hour, and then remove the immersed mullite fiber.

[0115] A2. The mullite fibers impregnated in A1 are dried at 90℃ for 12 hours to obtain dried mullite fibers.

[0116] A3. The dried mullite fiber from A2 was heat-treated at 900℃ for 4 hours to obtain modified mullite fiber.

[0117] The treatment method for secondary aluminum ash is to crush the secondary aluminum ash, then sequentially acid-soak and water-wash it, and finally dry it to obtain the treated secondary aluminum ash.

[0118] The treatment method for secondary aluminum ash after processing is as follows:

[0119] B1. Crush the secondary aluminum ash to a mesh size of 400 or finer to obtain crushed secondary aluminum ash;

[0120] B2. Mix hydrochloric acid with secondary aluminum ash at a weight ratio of 1:1 and a concentration of 5.0 wt% with the crushed secondary aluminum ash from B1, stir at room temperature for 8 hours, and then filter to obtain acid-leached secondary aluminum ash.

[0121] B3. Wash the acid-leached secondary aluminum ash from B2 with pure water until the pH of the washing solution is 7.5, and finally dry the solid to obtain the treated secondary aluminum ash.

[0122] The composition of the secondary aluminum ash from a certain recycled aluminum plant used in this embodiment is shown in Table 2:

[0123] Table 2. Composition of secondary aluminum ash in this embodiment

[0124]

[0125] The method for preparing refractory materials using secondary aluminum ash as raw material according to the present invention comprises the following steps:

[0126] S1. Mix the raw materials of the mixture according to the proportion, let it stand, and obtain the mixture.

[0127] S2. The mixture obtained in S1 is mixed with water and pressed into a blank under a pressure of 65 MPa and a holding time of 30 s. The mass ratio of the mixture to water is 1:0.8.

[0128] S3. The green body is subjected to high-temperature calcination at a heating rate of 5℃ / min, a temperature of 1250℃, and a time of 60min to obtain refractory material.

[0129] Example 4

[0130] A method for preparing refractory materials using secondary aluminum ash as raw material, with other features the same as in Example 1, except that: in the mixture, by weight percentage:

[0131] Secondary aluminum ash after treatment: 68.5 wt%;

[0132] Attapulgite: 6.5 wt%;

[0133] Limestone: 3.8 wt%;

[0134] Modified mullite fiber: 7.6 wt%;

[0135] Adhesive: 4.2 wt%;

[0136] Muscovite: Balance.

[0137] The modified mullite fiber is prepared by impregnating mullite fiber in a mixture of liquid phenolic resin, silica powder, and isopropanol. After impregnation, the fiber is dried and heat-treated sequentially to obtain the modified mullite fiber. The mass ratio of liquid phenolic resin, silica powder, and isopropanol in the mixture is 12:6.5:72, and the mass ratio of mullite fiber to the mixture is 4:9.

[0138] The preparation method of modified mullite fiber consists of the following steps:

[0139] A1. Immerse the mullite fiber in a mixture of liquid phenolic resin and silica powder for 1-3 hours, and then remove the immersed mullite fiber.

[0140] A2. The mullite fibers impregnated in A1 are dried at 82.5℃ for 10 hours to obtain dried mullite fibers.

[0141] A3. The dried mullite fiber from A2 was heat-treated at 856℃ for 6 hours to obtain modified mullite fiber.

[0142] The treatment method for secondary aluminum ash is to crush the secondary aluminum ash, then sequentially acid-soak and water-wash it, and finally dry it to obtain the treated secondary aluminum ash.

[0143] The treatment method for secondary aluminum ash after processing is as follows:

[0144] B1. Crush the secondary aluminum ash to a mesh size of 400 or finer;

[0145] B2. Mix hydrochloric acid with a weight ratio of 1:0.85 and a concentration of 5.0 wt% with the crushed secondary aluminum ash from B1, stir at room temperature for 6 hours, and then filter to obtain acid-leached secondary aluminum ash.

[0146] B3. Wash the acid-leached secondary aluminum ash from B2 with pure water until the pH of the washing solution is 7.0, and finally dry the solid to obtain the treated secondary aluminum ash.

[0147] The elemental composition of the secondary aluminum ash from a certain recycled aluminum plant used in this embodiment is shown in Table 3:

[0148] Table 3. Composition of secondary aluminum ash in this embodiment

[0149]

[0150] The method for preparing refractory materials using secondary aluminum ash as raw material according to the present invention comprises the following steps:

[0151] S1. Mix the raw materials of the mixture according to the proportion, let it stand, and obtain the mixture.

[0152] S2. The mixture obtained in S1 is mixed with water and pressed into a blank under a pressure of 63 MPa and a holding time of 60 s. The mass ratio of the mixture to water is 1:0.6.

[0153] S3. The green body is subjected to high-temperature calcination at a heating rate of 8℃ / min, a temperature of 1400℃, and a time of 150min to obtain refractory material.

[0154] Comparative Example 1

[0155] A method for preparing refractory materials using secondary aluminum ash as raw material, with other features the same as in Example 4, except that: in the mixture, by weight percentage:

[0156] Secondary aluminum ash after treatment: 50.0 wt%;

[0157] Attapulgite: 10.0 wt%;

[0158] Limestone: 8.0 wt%;

[0159] Modified mullite fiber: 3.0 wt%;

[0160] Adhesive: 4.2 wt%;

[0161] Muscovite: Balance.

[0162] Comparative Example 2

[0163] A method for preparing refractory materials using secondary aluminum ash as raw material, with other features the same as in Example 4, except that: in the mixture, by weight percentage:

[0164] Secondary aluminum ash after treatment: 75.0 wt%;

[0165] Attapulgite: 4.0 wt%;

[0166] Limestone: 1.0 wt%;

[0167] Modified mullite fiber: 13.0 wt%;

[0168] Adhesive: 4.2 wt%;

[0169] Muscovite: Balance.

[0170] Comparative Example 3

[0171] A method for preparing refractory materials using secondary aluminum ash as raw material is disclosed, with other features identical to those in Example 4, except that the modified mullite fiber is prepared by impregnating mullite fiber in a mixture of liquid phenolic resin, silica powder, and isopropanol. After impregnation, the fiber is subsequently dried and heat-treated to obtain the modified mullite fiber. The mass ratio of liquid phenolic resin, silica powder, and isopropanol in the mixture is 5:10:72, and the mass ratio of mullite fiber to the mixture is 4:9.

[0172] Comparative Example 4

[0173] A method for preparing refractory materials using secondary aluminum ash as raw material is disclosed, with other features the same as in Example 4, except that the modified mullite fiber is prepared by impregnating mullite fiber in a mixture of liquid phenolic resin, silica powder, and isopropanol. After impregnation, the fiber is subsequently dried and heat-treated to obtain the modified mullite fiber. The mass ratio of liquid phenolic resin, silica powder, and isopropanol in the mixture is 12:6.5:72, and the mass ratio of mullite fiber to the mixture is 8:3.

[0174] Comparative Example 5

[0175] A method for preparing refractory materials using secondary aluminum ash as raw material, with other features the same as in Example 4, except that in this example, modified mullite fibers are replaced by mullite fibers in the mixture.

[0176] Comparative Example 6

[0177] A method for preparing refractory materials using secondary aluminum ash as raw material, with other features the same as in Example 4, except that in this example, the secondary aluminum ash after treatment in the mixture is replaced by untreated secondary aluminum ash.

[0178] Comparative Example 7

[0179] A method for preparing refractory materials using secondary aluminum ash as raw material, with other features the same as in Example 4, except that: in the mixture, by weight percentage:

[0180] Secondary aluminum ash after treatment: 68.5 wt%;

[0181] Attapulgite: 14.1 wt%;

[0182] Limestone: 3.8 wt%;

[0183] Adhesive: 4.2 wt%;

[0184] Muscovite: Balance.

[0185] Comparative Example 8

[0186] A method for preparing refractory materials using secondary aluminum ash as raw material, with other features the same as in Example 4, except that: in the mixture, by weight percentage:

[0187] Secondary aluminum ash after treatment: 68.5 wt%;

[0188] Modified mullite fiber: 14.1 wt%;

[0189] Limestone: 3.8 wt%;

[0190] Adhesive: 4.2 wt%;

[0191] Muscovite: Balance.

[0192] Example of effect

[0193] The refractory materials of Examples 2 to 4 and Comparative Examples 1 to 8 were subjected to various performance tests, and the performance data are shown in Table 4. The test methods are as follows:

[0194] (1) Refractoriness: Tested in accordance with GB7322-87 Refractories Test;

[0195] (2) Softening start temperature: The temperature shall be determined in accordance with the "Test Method for Softening Start Temperature under Load" (YB370-75).

[0196] (3) Compressive strength at room temperature: Tested in accordance with GB / T5072-2008 Test method for compressive strength of refractory materials at room temperature;

[0197] (4) Reheating line change: The test shall be conducted in accordance with the "Test Method for Reheating Line Change of Dense Shaped Refractory Products" (GB5988-86).

[0198] (5) Thermal shock resistance: Tested in accordance with GB / T 30873-2014 Test method for thermal shock resistance of refractory materials.

[0199] Table 4. Performance data of refractory materials

[0200]

[0201] In summary, this invention, through a unique filler ratio, combines treated secondary alumina ash, attapulgite clay, limestone, modified mullite fiber, binder, and muscovite to create a refractory material with excellent refractoriness. It can withstand high-temperature environments exceeding 1784℃ and still maintain a softening temperature above 1562℃. Furthermore, the compressive strength and flexural strength of this refractory material are higher than those of the comparative example, exhibiting superior mechanical properties, thereby extending its service life and effectively preventing cracking.

[0202] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method for preparing refractory materials using secondary aluminum ash as raw material, characterized in that: Contains a mixture and water; The raw materials of the mixture include treated secondary aluminum ash, attapulgite, limestone, modified mullite fiber, binder and muscovite. The modified mullite fiber is prepared by impregnating the mullite fiber in a mixture of liquid phenolic resin, silica powder and isopropanol, and then drying and heat-treating it in sequence after impregnation to obtain the modified mullite fiber. The method for processing the secondary aluminum ash is to crush the secondary aluminum ash, then sequentially perform acid leaching and water washing, and finally dry it to obtain the processed secondary aluminum ash. The method for preparing the refractory material comprises the following steps: S1. Mix the raw materials of the mixture according to the proportion, let it stand, and obtain the mixture. S2. The mixture obtained in S1 is mixed with water and pressed into a blank under a pressure of 60MPa to 65MPa and a holding time of 30s to 120s. The mass ratio of the mixture to water is 1:(0.5 to 0.8). S3. The blank is subjected to high-temperature calcination at a heating rate of 5℃ / min to 10℃ / min, a temperature of 1250℃ to 1550℃, and a time of 60min to 240min to obtain the refractory material. In the mixture, by weight percentage: Secondary aluminum ash after treatment: 65wt%~70wt%; Attapulgite: 5wt%~8wt%; Limestone: 2wt%–5wt%; Modified mullite fiber: 5wt%~10wt%; Adhesive: 3wt%~5wt%; Muscovite: Balance; In the mixture, the mass ratio of liquid phenolic resin, silica powder and isopropanol is (10-15):(3-8):(60-80), and the mass ratio of mullite fiber to the mixture is (3-5):(5-10). The modified mullite fiber is prepared by the following steps: A1. Immerse the mullite fiber in a mixture of liquid phenolic resin, silica powder and isopropanol for 1 to 3 hours, and then remove the immersed mullite fiber. A2. The mullite fibers impregnated in A1 are dried at a temperature of 70℃~90℃ for 8h~12h to obtain dried mullite fibers. A3. The dried mullite fibers from A2 are heat-treated at a temperature of 750℃~900℃ for 4h-8h to obtain modified mullite fibers. The method for treating the secondary aluminum ash after the initial treatment is as follows: B1. Crush the secondary aluminum ash to a mesh size of 400 or finer to obtain crushed secondary aluminum ash; B2. Mix hydrochloric acid with a weight ratio of 1:(0.8~1) and a concentration of 5.0wt% with the crushed secondary aluminum ash from B1, stir at room temperature for 4h~8h, and then filter to obtain acid-leached secondary aluminum ash. B3. Wash the acid-leached secondary aluminum ash from B2 with pure water until the pH of the washing solution is 6.5-7.5, and finally dry the solid to obtain the treated secondary aluminum ash.

2. The method for preparing refractory materials using secondary aluminum ash as raw material according to claim 1, characterized in that, In the mixture, by weight percentage: Secondary aluminum ash after treatment: 68.5 wt%; Attapulgite: 6.5 wt%; Limestone: 3.8 wt%; Modified mullite fiber: 7.6 wt%; Adhesive: 4.2 wt%; Muscovite: Balance.

3. The method for preparing refractory materials using secondary alumina ash as raw material according to claim 2, characterized in that, In the mixture, the mass ratio of liquid phenolic resin, silica powder and isopropanol is 12:6.5:72, and the mass ratio of mullite fiber to the mixture is 4:

9.

4. The method for preparing refractory materials using secondary aluminum ash as raw material according to claim 3, characterized in that, The modified mullite fiber is prepared by the following steps: A1. Immerse the mullite fiber in a mixture of liquid phenolic resin, silica powder and isopropanol for 1-3 hours, and then remove the impregnated mullite fiber. A2. The mullite fibers impregnated in A1 are dried at 82.5℃ for 10 hours to obtain dried mullite fibers. A3. The dried mullite fiber from A2 was heat-treated at 856℃ for 6 hours to obtain modified mullite fiber. The method for treating the secondary aluminum ash after the initial treatment is as follows: B1. Crush the secondary aluminum ash to a mesh size of 400 or finer; B2. Mix hydrochloric acid with a weight ratio of 1:0.85 and a concentration of 5.0 wt% with the crushed secondary aluminum ash from B1, stir at room temperature for 6 hours, and then filter to obtain acid-leached secondary aluminum ash. B3. Wash the acid-leached secondary aluminum ash from B2 with pure water until the pH of the washing solution is 6.5-7.5, and finally dry the solid to obtain the treated secondary aluminum ash.

5. A refractory material using secondary aluminum ash as raw material, characterized in that, It is prepared by the refractory material preparation method using secondary aluminum ash as raw material as described in any one of claims 1 to 4.

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